Update on collagenous sprue.

Collagenous sprue has traditionally been defined as a small intestinal mucosal disorder characterized by persistent diarrhea, severe malabsorption with multiple nutrient deficiencies and progressive weight loss. Pathologically, a severe to variably severe "flattened" mucosal biopsy lesion with distinctive sub-epithelial deposits in the lamina propria region is detected. Histochemical stains and ultrastructural studies have confirmed that these deposits contain collagens. Often, an initial diagnosis of celiac disease is considered but no continued response to treatment with a gluten-free diet occurs. Recent reports indicate an intimate relationship between collagenous sprue and celiac disease, sometimes with concomitant T-cell enteropathy. In addition, permanent disappearance of these deposits after resection of a localized colon cancer suggested that this disorder could actually represent a paraneoplastic morphologic marker of an occult malignancy. Studies showing either gastric or colonic involvement (or both) with this unusual collagenous inflammatory mucosal process may also reflect a far more extensive and heterogeneous process than previously appreciated.